1. Field of the Invention
The present invention relates to a super-paramagnetic composite particle with core/shell structure, preparation method and use thereof. More particularly, the present invention related to this core/shell super-paramagnetic composite particle for labeling biological molecule and materials or non-biological molecules using the functional group consisted of nucleic acid, antigen, antibody, enzyme, polypeptide, polysaccharide, avidin, streptavidin, cell, and the like, the preparation method and the use thereof. The core/shell super-paramagnetic composite particle according to the present invention can be used in purification or detection of various biological molecules and other chemical molecules.
2. Description of the Related Art
Magnetic particles with nanometer size such as iron oxide are super-paramagnetically and magnetically responsive, which allows them to be separated repeatedly and without aggregation by manipulating magnetic field consisted of NdFeB permanent magnet. Super-paramagnetic nanoparticles coated with synthetic macromolecule, biological macromolecule and inorganic material have been widely used in biological and medical areas such as affinity chromatography, cell sorting, separation and purification of nucleic acid and protein, and targeted therapy. In addition, because mercapto labeled oligonucleotide or antibody is readily modified onto the surface of nano-gold or nano-silver, the uses of nano-gold and nano-silver in the areas of nucleic acid detection, immunoassay and the like is well known to those skilled in the art. Intensive studies regarding applying nano-gold modified with oligonucleotide probe in nucleic acid detection have been reported by Mirkin etc. (University of Northwest, USA) since 1996. The particle is used in DNA chip detection technology. CN 1339609 discloses a nanoparticle labelling gene probe, the preparation method and the use thereof (Daiwen Pang et. al., Wu Han University, China). It is reported that the probe is particularly suitable for low integrated level gene chip of diagnostic type.
A Fe3O4/Au super-paramagnetic particle with core/shell structure and the mechanism of preparation has been studied (Yali Cui et. al., Preparation and mechanism of Fe3O4/Au core/shell super-paramagnetic microspheres. Science in China (series B) 44(4): 404–410, 2001).